Macroscopic interference of interlayer phase coherence in Bi2Sr2CaCu2O8+y with inhomogeneous columnar defects

By measurements of Josephson plasma resonance (JPR), we study the interlaye r phase coherence in Bi2Sr2CaCu2O8+y single crystals with partially introdu ced columnar defects. In the half-irradiated Bi2Sr2CaCu2O8+y, we observe se veral resonances. which cannot be regard as a superposition of each constit uent parts. The frequency dependence of the highest resonance field. which is considered to be originated from the irradiated part, shows a cyclotron behavior which is different from the ordinary JPR. These facts indicate tha t the resonance field in a region is affected by the neighboring region wit h different phase coherence over a macroscopic scale. (C) 2001 Elsevier Sci ence B.V. All rights reserved.